260 HISTORY OF SCIENCE. 



he passed nearly every clear night in the open air observing the stars, 

 and his robust health enabled him to continue a practice which would 

 have been trying to many constitutions. In this way he began a 

 systematic survey of the heavens, and did not fail to be rewarded by 

 grand discoveries, which shall presently be mentioned. 



On the 1 3th of March, 1781, Herschel observed a small star in the 

 constellation Gemini, because this star appeared to have a steady 

 light, and even to have a sensible diameter, in this last particular dif- 

 fering notably from the fixed stars, to which no magnifying power 

 whatever can give the appearance of anything but mere /#////.? of light. 

 The position of the star among the rest was noted, and after some 

 hours another observation appeared to indicate a slight change in the 

 place. The next night's observations placed this change beyond a 

 doubt, and Herschel announced to Maskelyne, the Astronomer Royal, 

 that he had discovered a comet. Maskelyne confirmed Herschel's 

 conclusion, and sent word to the French astronomers of the position 

 of the supposed comet After the new star had been observed for 

 some time, attempts were made to calculate its orbit, on the supposi- 

 tion that the orbit was parabolic ; but it was soon perceived that the 

 real orbit was nearly circular, and that the object was a planet, and 

 not a comet. It will be an excellent illustration of the utility of cata- 

 logues of the stars, such as those made by Flamsteed and by Meyer, 

 to point out that this planet had been observed by the former as a 

 star (No. 34) in Taurus, and also by the latter, in whose catalogue it 

 appears as No. 964. As positions of the planet at given moments, 

 included within about a century of observation, were thus accurately 

 known to astronomers, they were at once able to calculate the "ele- 

 ments " of the new planet with great precision. Herschel proposed to 

 give to the new member of the solar system the name of Georgian 

 Sidus (the Georgian Star) in honour of George III. ; but this termi- 

 nology did not find much favour in the scientific world, and a French 

 astronomer suggested that the new planet should be known by the 

 name of its discoverer. Both names were superseded by a more ap- 

 propriate appellation given to the planet in Germany, where the old 

 plan of assigning a name from classical mythology was adhered to, 

 and the name of the most ancient of the gods, Uranus, was bestowed 

 on the outermost (as then supposed) body in our system. The dis- 

 tance of Uranus from the sun was found to be 180,000.000 miles, and 

 the period required to complete one orbital revolution eighty-three 

 of our years. 



The genius of the Bath musician, who was now reading mighty 

 secrets in the stars, became fully known by this discovery ; and as his 

 powers were obviously fettered by the conditions under which he was 

 working, the King (George III.), with commendable liberality set 

 Herschel free to follow the bent of his genius, by bestowing upon him 

 in 1782 a pension of ^300 a year, whereupon he took up his resi- 



